Private/Update-DefaultArguments.ps1

function Update-DefaultArguments
{
    [cmdletbinding()]
    param($inputObject)
    
    if($InputObject.ContainsKey('LayoutEngine'))
    {
        Write-Verbose 'Looking up and replacing rendering engine string'
        $InputObject['LayoutEngine'] = Get-LayoutEngine -Name $InputObject['LayoutEngine']
    }

    if( -Not $InputObject.ContainsKey('DestinationPath'))
    {
        $InputObject["AutoName"] = $true;
    }

    if( -Not $InputObject.ContainsKey('OutputFormat'))
    {
        Write-Verbose "Tryig to set OutputFormat to match file extension"
        $outputFormat = Get-OutputFormatFromPath -Path $InputObject['DestinationPath']
        if($outputFormat)
        {
            $InputObject["OutputFormat"] = $outputFormat
        }
        else 
        {
            $InputObject["OutputFormat"] = 'png'
        }
    }
    
    return $InputObject
}